Alogliptin, dipeptidyl peptidase-4 (DPP-4) inhibitor, Pioglitazone, thiazolidinediones (TZDs) and Metformin, biguanides are antidiabetic drugs that usually used in the management of type 2 diabetes that can be used solely or as combinations. In this article, a selective, simple, economical, precise, and stability-indicating RP-HPLC method has been developed and validated for assessing Alogliptin, Pioglitazone, and Metformin inside the bulk drug and tablet pharmaceutical dosage form. The mobile phase that used to separate the drug was consists of acetonitrile: buffer (potassium dihydrogen phosphate), (30 : 70 v/v) on an ACE C18 ñ (250 mm × 4.6 mm), 5 µm column at a flow rate of 1.0 mL/min at 25 O C and detection was at 230 nm. The linearity of the detector was established in concentrations ranging from 20-250 ppm; the regression coefficient was 0.9998. The ICH guidelines were followed to evaluate stability, where the API is stressed by acid, base, neutral, oxidation, and sunlight. Several parameters were used for validation, including linearity, precision, accuracy, the limit of detection, and limit of quantification. The results were fulfilling expectations based on ICH guidelines. Robustness of the method was verified in terms of changes in pH of the mobile phase, detector wavelength, mobile phase composition, and temperature. Also, the method results in low relative standard deviation and high recovery value, that ensure the convenience applicability of the method for routine analysis of tablet containing Alogliptin, Pioglitazone, and Metformin.